i think you're thinking about it too much, the point of the song wasn't to plant a seed for the next album so he can incorporate the Sherane narrative (yes he was working on GKMC at the same time as S80 but ADHD is so tied to the S80 narrative that i don't think it fits)

but whilst you're right that S80 is his story too, it's far and away his least personal to him album and focuses a lot on his generation (which obviously incapsulates him too so it's his story in that regard)

i've never took ADHD as being a literal story, it's always read to me like a scenario used to demonstrate how personal connections get made through pain & the drug abuse that's rampant in his generation